Migraine: Abortive drug therapy

Almost all migraineurs who experience at least occasional attacks of moderate or severe headache are candidates for treatment with an abortive agent. Some general caveats for the use of abortive drug therapy follow.

1. Use a therapeutic dose at the appropriate time: An adequate dose of aspirin or acetaminophen (say, 975 mg, especially taken in conjunction with a caffeinated beverage) administered early in a migraine attack may be more effective than a “powerful” opioid (narcotic) taken too late. When patients tell us that “simple” analgesics have failed in the past, we are careful to ask them what dosage was used and at what point in the attack the medication was taken. Especially with over-the-counter (OTC) medications, the “recommended” doses often are insufficient to terminate acute migraine.

2. Match drug to headache intensity: There is no single drug that is ideal for the treatment of migraine headache regardless of pain intensity. Some agents will work only-or at least consistently-if taken when the headache is mild to moderate in intensity, and others (e.g., injectable sumatriptan) ironically may have little effect on early headache but relieve excruciating head pain completely. Evidence is rapidly accumulating to suggest that the oral triptans (see Appendix 3) are most effective and most consistently effective-when taken early in an attack, when the pain is still relatively mild.

3. Treat early: This caveat serves to some extent as a corollary to #1 and #2. As an attack progresses, the pain pathways within the central nervous system become sensitized, resulting in reduced drug effectiveness and a higher incidence of drug-related side effects. If you have mild headaches that never progress, it is reasonable to have a different medication for that headache. However, if your attack is generally disabling, never “step up” to the most effective drug: treat with that agent early on.

4. Use the appropriate formulation: Use the appropriate formulation. It makes no sense to take an oral medication for acute migraine if you are experiencing associated nausea and vomiting; that situation calls for medication that is administered intranasally, rectally, subcutaneously (i.e., injection under the skin) or in some other fashion that will enable the drug to be absorbed by the body and do its job. If the nausea is experienced some time after the attack begins, the pills will probably suffice; if these symptoms are experienced early in the attack, then the agent will never be absorbed and it is doubtful that it will be effective.

5. Even when vomiting is not a problem, the oral administration of acute migraine medication may be complicated by erratic gastrointestinal absorption; acute migraine frequently produces gastric paresis (i.e., delayed stomach emptying), resulting in impaired absorption. A way to overcome this obstacle is to take caffeine along with any other orally administered medication; a more expensive alternative is to administer oral metoclopramide (Reglan), like caffeine an agent that promotes gastric emptying, about 20 minutes before taking another oral drug intended for acute migraine treatment. The newer migraine agents; triptans, all reduce nausea and vomiting in parallel with reduction in headache.

6. Avoid overuse: We will explore the issue of analgesic overuse headache in detail later in this chapter, but for now, medication intended for the acute treatment of migraine actually may promote headache if it is overused. Along with this, overuse of certain analgesics rapidly may lead to tolerance, wherein the pain killing effect of the drug progressively decreases with continued use. Tolerance may provoke a vicious cycle, enticing the patient to take more and more of an analgesic to obtain less and less pain relief and may lead to physical and psychological drug addition.

The abortive medications commonly used for migraine are listed and briefly described in Appendix 3. When you receive a prescription for such medication, be sure you understand how and when it is to be used, what side effects you may anticipate and what to do should the drug prove ineffective. To ensure that you do not receive a prescription for an abortive medication that might cause a serious side effect or interact adversely with other medications you are taking, provide your physician with a complete medical history (emphasizing any problems you may have had with blood pressure, heart disease, diabetes or gastrointestinal disorder such as peptic ulcer disease). Also, be sure to provide a complete listing of your medications and their current dosages.

The ideal abortive agent for headache is one that is inexpensive, easy to administer, exerts its therapeutic effect rapidly, invariably terminates the headache completely, does so without conveying side effects, is associated with a 0% chance of early headache recurrence and possesses no potential for producing analgesic overuse headache. Needless to say, no such agent yet exists, but in designing an acute headache treatment strategy, this is the ideal for which we should strive.